<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<script>
    for (var j = 0; j < 10; j++){
        for (var i = 0; i <= j; i++){
            document.write("*");
        }
        document.write("<br>");
    }
</script>


</body>
</html>